[SI-LIST] Re: DDR point to point termination
- From: "Landrum, Chris" <chris_landrum@xxxxxxxxxx>
- To: <arich1970@xxxxxxxxxxx>, <si-list@xxxxxxxxxxxxx>
- Date: Tue, 13 Jul 2004 13:01:52 -0400
I have implemented a point to point DDR interface (200MHz) using series
resistors located in the middle of the data traces. I have seen the
same app note you speak of requiring the trace lengths to be less than
2in, which seems to work well in my application. =20
However, you describe a DDR interface consisting of 4 devices. This is
not point-to-point as the devices will share data lines. This interface
should be simulated.
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]
On Behalf Of Aric Hadav
Sent: Tuesday, July 13, 2004 11:24 AM
To: si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] DDR point to point termination
Hi,
I'm designing an embedded system with DDR. I'm using a CPU connected to
an=20
on board four 16 bit DDR devices (no DIMM).
I have 2 questions though -
1. can I use only a series termination on the data bus (I saw a few AN
that=20
state that if the disctance between the controller and the DDR IC's is
upto=20
2" its ok). has anyone did it with a 200MHz clock ?
2. since the address and control lines operate in half the data rate and
the=20
DDR controller is very lightly loaded (only 4 chips) can I use only
series=20
termination for address and control ? has anyone did it with good
resaults ?
thanks,
Aric
_________________________________________________________________
Add photos to your messages with MSN 8. Get 2 months FREE*.=20
http://join.msn.com/?page=3Dfeatures/featuredemail
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List FAQ wiki page is located at:
http://si-list.org/wiki/wiki.pl?Si-List_FAQ
List technical documents are available at:
http://www.si-list.org
List archives are viewable at: =20
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
=20
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List FAQ wiki page is located at:
http://si-list.org/wiki/wiki.pl?Si-List_FAQ
List technical documents are available at:
http://www.si-list.org
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
